The present invention relates to methods of formulating dairy cow rations to optimized milk yield, and more particularly to such methods which are based upon regulation of the non-structural carbohydrate content of the total ration and the ratio thereof to the neutral detergent fiber content.
U.S. Pat. No. 4,118,513, assigned to applicants' assignee, describes a method of formulating dairy rations based on adjustment of the proportions of soluble and insoluble protein in the total dietary protein to obtain a positive response in milk production. The present invention is the result of research directed toward determining the optimum balance of structural and non-structural carbohydrates in dairy cow rations for increased milk production and feed efficiency.
It is well known, of course, that carbohydrates are the principal energy source for many animals, as well as humans. Plant carbohydrates may be categorized in two major groups, namely, structural and non-structural. The structural carbohydrates, found in the cell wall, are essentially rigid in nature, providing strength to the cell walls and thus to the plant itself. The fibrous materials which make up the cell walls, i.e., the structural carbohydrates, also known as neutral detergent fiber, are mainly cellulose, hemicellulose, and ligin. Non-structural carbohydrates, found mainly within the lumen of the cell, inlude sugars and starch. Although pectins (D-methyl-galacturonic acid) are a soluble component of the cell wall, they are almost completely digestible (98%) in the rumen. In addition, they are precipitated out of the cell wall by ethylene diamine tetra acetic acid (EDTA) which is contained in neutral detergent solution. A significant amount of pectin substances are contained in leguminous feedstuffs fed to animals (e.g. alfalfa, soybean meal, beet pulp, etc.) These pectin substances may physically be associated with the cell wall, but chemically they are associated with and behave like cell solubles; therefore, they are also considered a part of the non-structural carbohydrates.
The major source of structural carbohydrates in dairy cattle rations is forage. The quality and degree of structural carbohydrate availability (digestability) to rumen microorganisms in different forages are quite variable, being influenced by such factors as plant variety, maturity at harvest and storage conditions. Grains generally have more non-structural carbohydrates and are generally less variable in carbohydrate content than forage.
It has been generally accepted that structural carbohydrate is a negative indicator of ration energy concentration. That is, the more structural carbohydrate a given ration contains, the less energy value it provides, and vice versa. Present energy-based feeding systems for ruminants are based on this relationship.
In order to develop a feeding system which includes regulation of carbohydrates in the total daily ration, it is necessary, of course, to have available an accurate and repeatable method of quantitating both structural and non-structural carbohydrates in each constituent of the ration.A procedure which has been found to be superior to those previously in general use is disclosed in the aforementioned parent and divisional applications and is the method used for determining the non-structural carbohydrate content of feedstuffs in the practise of the present invention.
In the most general sense, the object of the present invention is to provide methods of formulating dairy cow rations which have a positive influence on milk production without an off-setting increase in the cost of the feeding program.
A further object is to provide a method of formulating dairy cow rations based upon regulation of the ratio of non-structural carbohydrates to neutral detergent fiber in the total daily ration, including both forage and grain portions.
Another object is to provide methods of balancing carbohydrate and protein types in dairy cow feeding programs which maximize efficiency of microorganism growth and yield, fiber digestion and overall feed efficiency, and milk production.
Other objects will in part by obvious and will in part appear hereinafter.